Bulb for pneumatic warning horns



J. F. SMITH.

BULB FOR PNEUMATIC WARNiNG HOR NS.

APPLICATION FILED SEPT. 26. l92l.

1,427,497. A Patented Aug. 29, 1922,

3 SHEETS-SHEET I.

I. F. SMITH.

BULB FOR PNEUMATICv WARNING HORNS.

Patnfed Aug. 29, 1922.

APPLICATION FILED SEPT-26,1921.

3 SHEETS-SHEET 2.

J. F. SMITH.

BULB FOR PNEUMATIC WARNING HORNS,

APPLICATION FILED SEPT- 26. I921.

PatentedAug. 29, 1922,

3 SHEETS-SHEET 3.

PATENT OFFICE.

JAMES-FREDERICK SMITH. or BIRMINGHAM; ENGLAND;

BULB FOR PNEUMATIC WARNING HORNS/ To ail whom it may concern:

Be it known that 1, James FREDERICK SMrrI-I', subject of the Kingof Great Britain,

residing at Birmingham, England, have invented certain new and useful Improve ments Relating to Bulbs for Pneumatic Warning Horns, of which the following is a specification. r

This invention relates to the manufacture of the india-rubber bulbs of pneumatic Warning horns used on motor-cars, motorcycles and the like. i

The object of the present invention is to ensure the hole in the neck being perfectly true and central, to render the bulb more durable and eiiicient in use, and to avoid the formation of internal shoulders or pockets likely to interfere with the free discharge of the air from the bulb, thus giving a quicker action. I

The invention consists essentially in moulding and vulcanizing the mouth ofthe bulb upon a thickenedneck part separately moulded or otherwise formed and having its inner eud flush with and merging into the tapered interior surface of the bulb, without any pockets or shoulders.

Figure 1 of the drawings shows a bulb, partly in section. manufactured according to this invention.

Figures 2' and 3 are views showingthe first stage of manufacture.

Figure 4 is a view showing the second stage of manufacture.

Figure 5' is a sectional elevation of a modified form of bulb.

Figure 6 is a-section showing the first stage of manufacture of this modification.

Figure 7 shows the body of the bulb being moulded to the neck. I

Figure 8 represents a further modified form of bulb neck.

Figure 9 shows the first stage in the manu facture of this modification.

Figure 10 represents the body of the bulb being moulded upon the neck.

Figure 11 illustrates, in section, a further method of forming the neck, the bulb being shown in the mould.

Figure 12 is a section through the. completed neck of a bulb .made in accordance with this further method.

Referring to Figures 1 to 4,41 short length of metal, vulcanite, ebonite or other suitable tubing 1 is taken and covered with a com- Specification of Letters Patent.

Patented A11 2 9,- 1922.

Application filed se temberae', i921. serial in). 563,439.

pound of plastic rubber or like material 2 as" is clearly seen at'Fig'ures 2 and 3.".Tliis covering. which constitutes the neck of the buib nay takethe form of a flat strip of plastic material which is wrapped or coldpressed around the 'tube or"; it may be of tubular formation formed" by forcing the plastic material through an annular orifice.

The body 3 of the bulb is cut in sections in the usual manner, and the mouth moulded around or oinedto'the'neck 2 and the whole placed in a mould 4.21s shown in Figure 4, the outer end of tube 1 being closed by aplug 5 or by a cap or other means. and the bulb'is inflated byammonia gas in the well known manner. jected-t'o a process of vulcanization; so that thei'tube 1, the co ering" or; neck 2am the body of the bulb date all vulcanized togethcr, the bulb and the neck 2 forming a homogeneous whole. 7

The interior end of the'neck of the bulb acent theinner end of the tube is shaped so as to be of regular contour flush with theinterior' surface of the bulb without any recesses 01' cavitiesinto which the air can be pocketed when the bulb is deflated; this is clearly shown at Figures 1 and 4.

If desired a ferrule (not shown) may be passed over the neck of the bulb to same a more finished appearance; I

By constructing a bulb asabove described I dispense with the costly and unsatisfactory method of making the neck of the bulb s re solid] and subsequently drilling same, and

I also provide a bulb which is stronger and i'i'iore ei'ficieiit and durable in use than those heretofore"provided while at the same time the cost of manufacture is considerably'reduced. I M i Instead of the'tube 1 being of metal it may be of ebonite, vulcanite. wood fibre or other suitable material.

In the case where the tube 1 is made of metal it is preferable to vulcanize' a thin covering or sleeve of ebonite upon the same prior to the rubber neck 2 being applied and vulcanized to it.

Referring to the modification represented in Figures 5 to 7. an interior metal or other tube for connecting the bulb to the horn, and permanently vulcanized within the neck, is dispensed with. so that a fitting can be subsequently provided which is capable of being applied to all existing types of horns.

i The whole is then subvmetal or other tube .L

In carrying out the manufacture of this modification, a metal or other rigid tube 1 is taken and the exterior surface is dusted with powdered talc (French chalk) or other suitable material. which will prevent the neck from adhering to the tube during the subsequent process of vulcanization hereinafter described. The tube 1 is covered with a compound of plastic rubber or like material 2, as shown in Figure 2. This covering 2, which constitutes the neck of the bulb, may take the form of a flat strip of plastic material wrapped around the tube 1, or it may be of tubular form, drawn over the said tube. The body 3 of the bulb is cut in sections and the mouth moulded around or jointed to the neck 2 in the usual manner, the said sections of the body having their edges united. The body 3 of the bulb together with the tube 1 bearing the neck 2, are placed in a mould at, as shown in Figure 7. The outer end of the tube 1 isclosed by a plug 5 or by a cap or other means, and the bulb is inflated by ammonia gas in the well-known manner. The whole is then subjected to a process of vulcanization. After vulcanization the tube 1 is Withdrawn, the application of powdered talc preventing it from adhering to the neck. A cir-l cular hole is thus left in the latter, in which various types of fittings can be inserted and secured. he inner end of the neck 2 is shaped so as to merge into and l e flush with the inside tapered surface of the bulb.

In the modification represented in Figures 8 to 10, the interior of the rubber neck 2 is reinforced by a sleeve 6 of ebonite, vul-- canite or the like, which does not, however, constitute a fitting for connecting the bulb to the horn, A metal fitting for effecting this connection can be inserted into and securedwithin the sleeve (5. In carrying outthe manru acture oi this modification, a

French chalk, and covered by a strip or sleeve of ebonite or vulcanite 6, as shown in Figure 5. Upon this sleeve 6 the rubber neck :2. is moulded or otherwise applied, and finally the mouth of the body 3 of the bulb is moulded-upon the neck in the mould is taken, dusted with 4-, as shown in Figure 10, and as described in connection with Figures 5 to 7. The whole is then vulcanized. and the tube 1 withdrawn. The inner end of neck 2 is shaped to come flush with the bulb body as previously described.

According to the further modification shown in Figure 11, a solid plug of rubber 2 is placed in a mould a and the mouth of the bulb body moulded and vulcanized around the said pin", the inner end of the latter being shaped so as to merge into and come flush with the interior surface-of the bulb. After removal from the bulb, the

plug 2 is drilled centrally, as shown in Figure 13, thus forming the neck, into which the connection fitting of the bulb can be inserted.

Having fully described my invention, what I desire to claim and secure by Letters Patent is LA bulb for pneumatic warning horns comprising a hollow body part the mouth of which is moulded and vulcanized upon a separately formed thick rubber neck part the inner end ot which is flush with and merges into the interior surface or the hollow body part of the bulb.

A bulb for pneumatic warning horns comprising a hollow body part the mouth of which is moulded and vulcanized upon thick rubber neck part which is separately formed upon a central tube, the inner end of the neck part being flush with and merging into the interior surface of the body part.

3. A bulb "for pneumatic warning horns comprising a hollow body part the mouth of which moulded and vulcanized upon a thick rubber neck part which is separately formed and permanently secured upon a central tube forming the means for connecting the bulb to the horn.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses. i

J. F. SMITH.

Witnesses:

H. L. SKERRETT, W. S. 

